A novel microwave photonics-based de-chirp radar receiver which breaks the limitation of the detection range swath is proposed and demonstrated. In the proposed receiver, a multi-channel time-division photonics de-chirp processing is implemented to increase the detection range swath. A linear frequency modulated pulse train is sent to multiple reception channels and temporally delayed in the optical domain to form reference signal replicas, enabling time-division photonics-de-chirp processing with echoes reflected from different distance regions so that the total detection range swath is increased and determined by the number of reference replicas. Hardware-in-the-loop simulation experiments are demonstrated and an inverse synthetic aperture 2D imaging is carried out, showing that the MWP radar with the proposed photonics de-chirp receiver is capable of achieving a detection range swath of 13km which is 20 times larger than that when employing a conventional de-chirp receiver with the same parameters.A material platform of highly c-axis oriented Zn1-xMgxO thin films is developed for nonlinear planar waveguides and electro-optic modulators on Si. Mg content in the film greatly influences the quality of film growth. The second harmonic generation measurement and Maker-fringe analysis reveal that the second-order nonlinear susceptibility tensor element χ33 of the annealed Zn0.72Mg0.28O is approximately 4.2 times larger than that of ZnO. The propagation loss of 633 nm wavelength light in the annealed air/Zn0.72Mg0.28O/SiO2 slab waveguide is 0.68?±?0.09 dB/cm and 0.48?±?0.03 dB/cm for the TE0 and TM0 modes, respectively. These results suggest the great potential of the c-axis oriented Zn0.72Mg0.28O nonlinear planar waveguides for applications in on-chip optical interconnects.We optimized the p-side emission device configuration of photonic-crystal surface-emitting laser (PCSEL) to facilitate the easier chip process and wafer level testing as well as the feasibility of lasing at shorter wavelength. Typically, in order to obtain uniformly distributed current for larger emission area of PCSELs, laser output is designed through the n-side window due to the low hole mobility and thin p-side cladding layer. However, the substrate as well as the epi-layers have to be isolated before the test of each single die on the wafer, which compromised the advantage of wafer-level test of surface emitters. On the other hand, for lasers with emission photon energy higher than the bandgap energy of GaAs substrate, the power will be entirely attenuated. https://www.selleckchem.com/products/Isradipine(Dynacirc).html In this study, the optimized p-side emission by applying the transparent conduction layer on top of the p side contact layer to enhance the current distribution and breaking the symmetry of conventional circle pattern in a unit cell to boost the output efficiency is investigated. Through this approach, a high efficiency p-side up PCSEL platform with lower fabrication cost is developed, which is also applicable for short wavelength PCSELs.Recently, chirped and tilted fiber Bragg gratings (CTFBGs) have received great attention because they can realize suppression of stimulated Raman scattering (SRS) in high-power fiber lasers. In this study, the possible coupling between the core modes and cladding modes in CTFBGs inscribed in large-mode-area double-cladding fibers is investigated for the first time. Theoretical results show that the coupling between the LP11 mode and cladding modes would destroy the transmission spectra envelope only considering the coupling of LP01 for single-mode CTFBGs, which will degenerate the SRS suppression performance. This was confirmed experimentally by measuring the spectral response under different mode excitations. A reliable method is demonstrated to ease the LP11-excitation-induced spectral deterioration by choosing an appropriate chirp rate for the inscription of CTFBGs, which is useful for improving the Raman suppression effect of large-mode-area double-cladding CTFBGs in high-power fiber lasers.We report GaSb-based laser diodes (LDs) grown on on-axis (001) Si substrates and emitting at 2.3 ?m. Two series of LDs were studied and compared. For the first series, a GaAs-based buffer layer was first grown by metal organic chemical vapor deposition (MOCVD) before growing the laser heterostructure by molecular-beam epitaxy (MBE). For the second series, a MOCVD GaSb buffer layer was added between the MOCVD GaAs buffer layer and the MBE laser heterostructure. Both series of LDs exhibited threshold currents in the 50-100 mA range and several mW output power at room temperature. They demonstrated continuous wave operation (CW) up to 70°C (set-up limited) without thermal rollover. Broad area LDs exhibited record threshold-current densities in the 250-350 A.cm-2 range for the second series of LDs, in spite of cracks that appeared during device processing. These results show that the design and fabrication steps of the buffer-layer stacks are critical issues in the epitaxial integration of GaSb-based optoelectronic devices on Si substrates and offer room for much performance improvement.We evaluate improvement in the performance of the optical transmission systems operating with the continuous nonlinear Fourier spectrum by the artificial neural network equalisers installed at the receiver end. We propose here a novel equaliser designs based on bidirectional long short-term memory (BLSTM) gated recurrent neural network and compare their performance with the equaliser based on several fully connected layers. The proposed approach accounts for the correlations between different nonlinear spectral components. The application of BLSTM equaliser leads to a 16x improvement in terms of bit-error rate (BER) compared to the non-equalised case. The proposed equaliser makes it possible to reach the data rate of 170 Gbit/s for one polarisation conventional nonlinear Fourier transform (NFT) based system at 1000 km distance. We show that our new BLSTM equalisers significantly outperform the previously proposed scheme based on a feed-forward fully connected neural network. Moreover, we demonstrate that by adding a 1D convolutional layer for the data pre-processing before BLSTM recurrent layers, we can further enhance the performance of the BLSTM equaliser, reaching 23x BER improvement for the 170 Gbit/s system over 1000 km, staying below the 7% forward error correction hard decision threshold (HD-FEC).